NSI-189 prevents PNS and CNS neuropathy in type 1 diabetic mice. A: Acquisition phase in the Barnes maze (day 5 of training, week 11 of diabetes and treatment). B: Memory retention (week 15 of diabetes and treatment). C: Short-term memory using the object recognition test after 16 weeks of diabetes. CA1 volume (D), CA3 volume (E), DG volume (F), MNCV (G), paw tactile 50% PWT (H), paw thermal response latency (I), paw IENF density (J), and nerve density in the corneal subbasal plexus (K) after 16 weeks of diabetes and treatment. C, control mice treated daily with vehicle; S, STZ mice treated daily with vehicle; SI, STZ mice with insulin pellet; SNSI, STZ mice treated daily with oral NSI-189. Data are mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001 by one-way ANOVA, followed by the Dunnett post hoc test (n = 8–10/group).